1. Field of the Invention
The invention relates to the field of offshore subsea oil and gas drilling and production operations. Specifically the invention relates to a hydraulically and/or mechanically driven junction plate actuator suitable for use in connecting and/or disconnecting a dynamic junction box half to a fixed junction box assembly.
2. Description of the Prior Art
Disconnectable hydraulic and electrical junction boxes are utilized in many subsea control and intervention applications. These applications include subsea blowout preventer (B.O.P.) stacks, production trees, production tree installation and workover systems, manifold systems, and interface systems. The applications may include direct control interfaces where remote installation is necessary and back up (intervention) to a main control module in the event of system failure.
Current disconnectable junction box assemblies consist of a fixed plate containing both checked and balanced hydraulic couplers and in some cases wet make/break electrical couplers. The fixed plate is mounted to the junction box assembly. A particular coupler can interface to the function to be controlled via hard pipe, hydraulic hose, or electrical pigtails.
The matching or dynamic plate containing the male or female coupler half interfaces to the fixed plate and is locked in place providing communication from the dynamic plate umbilical or cable through the couplers or electrical connector. In some cases, this mating interface is accomplished by utilizing a remote operated vehicle (R.O.V.) to manipulate the dynamic junction half to the assembly receiver interface via a flying-lead assembly.
Prior art systems employed for installation and makeup of a junction plate assemblies have consisted of a keyed female receiver funnel and matching male plug assembly, which is keyed and locked into the female receiver via the R.O.V. tooling end effector or coupling which rotates the locking dogs or similar detent mechanism in place. In turn, a mechanical screw, also driven by the R.O.V. tooling end effector, provides the makeup and breakout of the dynamic junction plate half to the fixed junction plate half.
The functionality of the prior art system described above is limited. For example, there are cases where hydraulic extend/retract functionality is desired. In such cases, hydraulic actuation to make and break the junction box halves provides the means to disconnect and retract the dynamic junction box half from the fixed assembly without intervention from the remote operated vehicle (R.O.V.). This may be advantageous in operations where the R.O.V. is being used for alternate tasks or is on surface for servicing or repair.
Additionally, there are distinct advantages in some applications in having a manual mechanical override function in the case of hydraulic system failure. This provides a redundancy provision in the method of operation providing the means for both hydraulic and mechanical actuation. Prior art systems do not provide a combined hydraulic and manual mechanical override capability, and are thus limited in functionality.